(1) Field of the Invention
The present invention relates to a method and an apparatus for exposing and recording color separation picture by photoelectrically scanning an original picture, and particularly to those which record desired areas of the original color picture by trimming the original picture.
(2) Description of the Prior Art
In recent photomechanical process rationalization in manufacturing processes for plate making and layout sheet advances, and a layout scanner in which a large part of the process is effected electronically has been successfully implemented. However, the conventional techniques such as "manual composing process" in which films having been color separated from each of original color pictures are applied onto a base sheet manually is still widely utilized.
In order to make the manual composing processes more facile, a method for separating a plurality of color original pictures collectively in which in order to make color separation more facile the color original pictures themselves are applied onto the base sheet according to a desired layout, and then they are photoelectrically scanned has been disclosed, for example, Japanese Patent Laid-Open Publication No. 59-226348 (the corresponding foreign patent applications are U.S. Ser. No. 616,389, GB No. 84 13578, DE No. P-34 20 482.2 and FR No. 84 08837) etc.
In the publicly known apparatus, as shown in FIG. 11, a base sheet (C) on which a plurality of color pictures (B1), (B2), and (B3) are applied to according to a predetermined layout is loaded on a scanning drum (A) of the color scanner and photoelectrically scanned, and the thus obtained reproduced picture images of these original pictures are recorded to a photographic film (E) loaded on a recording drum (D) as color separated halftone pictures with same size.
In this case, for the plurality of color pictures (B1), (B2) and (B3), secondary originals reproduced on a color duplication film or a paper from the respective original pictures with a magnification indicated in the layout by an appropriate duplication film are used, and in order to make it possible to simultaneously process by the color scanner, one set of the secondary originals pasted up on the same base (C), in case of necessity, a transparent film of a white paper register marks being attached, are arranged so that characteristics such as gradation, density range etc. are of the same degree.
In addition, in the case of letters or line drawings etc. being composed of the color pictures, negative films (F) thereof are made, and on the other hand, a trimming film (G) in which a desired area to be trimmed of the secondary originals is made to a window-like transparent portion and the other portion is made to an opaque is specially manufactured, and the base sheet (C) on which the secondary originals are pasted up and further overlapped with the trimming mask film (G) and the negative film (F) such as said letters etc. are carried out contact print on a new film (H). Thus, a positive film (J) composed of the original color pictures, letters etc., i.e., an original film for scanner working, is obtained.
In the above-described multiple contact printing work, a quite accurate registering is requested, and particularly, in the case of the pictures themselves being abuttedly disposed, a plurality of mask films are necessary and more further accurate registering is needed.
As another method, there is a scanning method in which the secondary originals duplicated from the original pictures are cut to desired trimming size and pasted on a transparent sheet, then the transparent sheet is loaded on a scanning drum of a color scanner on the surface of the transparent sheet, i.e., making the surface to the inside surface. However, in this method it is considerably difficult to cut practically the secondary originals to the desired size, and after color separation having been finished if there is any modification in the trimming size, other troublesome works to form the secondary originals again are necessary.
Further, in the Japanese Patent Laid-Open Publication No. 59-226343 filed by the very Applicant, there is disclosed another scanning method in which a desired rectangular trimming mask is electronically superposed to an original picture, and is exposed and recorded by scanning together with letters or line patterns. However, according to this method, configuration of trimming is limited to a rectangle, and can not be trimmed freely.